Search found 5449 matches

by mediatechnology
Sat Sep 25, 2010 5:09 pm
Forum: Pro Audio Design
Topic: LC filter experiments, in Pultec MEQ context
Replies: 15
Views: 31722

Re: LC filter experiments, in Pultec MEQ context

I assume you mean keeping the same sort of network, and just floating it all, as opposed to doing a truly balanced network with 2x parts. This sounds worth hearing. I wonder what typical inductor headroom really is, and how much they differ comparing original versus the various clones, and then how...
by mediatechnology
Sat Sep 25, 2010 3:38 pm
Forum: Pro Audio Design
Topic: LC filter experiments, in Pultec MEQ context
Replies: 15
Views: 31722

Re: LC filter experiments, in Pultec MEQ context

What I was suggesting is a little different. What I'm proposing here is a hybrid Pultec with solid-state electronics that is (almost) fully balanced end-to-end. 1) Lift the ground line at the input transformer and remove the transformer. Receive the input with a 1246 as you've done already. 2) Here'...
by mediatechnology
Sat Sep 25, 2010 2:34 pm
Forum: Pro Audio Design
Topic: Centralized B+ and AC filament power distribution
Replies: 11
Views: 20689

Re: Centralized B+ and AC filament power distribution

So no 12AX7/12AT7 anywhere.
by mediatechnology
Sat Sep 25, 2010 2:32 pm
Forum: Pro Audio Design
Topic: LC filter experiments, in Pultec MEQ context
Replies: 15
Views: 31722

Re: LC filter experiments, in Pultec MEQ context

One of Eugene's patents at RCA deals with an AM modulator. He may have spent some time in their broadcast division. https://twin-x.com/groupdiy/albums/userpics/meq5_updated_2008~0.jpg I'd like to see someone try the MEQ/PEQ network driven differentially by a THAT1646 (or dual current-boosted pair of...
by mediatechnology
Sat Sep 25, 2010 12:07 pm
Forum: Pro Audio Design
Topic: LC filter experiments, in Pultec MEQ context
Replies: 15
Views: 31722

Re: LC filter experiments, in Pultec MEQ context

Doug - I did a patent search for Eugene Shenk and it appears that a large body of his work was in telegraph systems and pulse reconstruction/synchronization. Most of his work looks to be assigned to RCA. I never could figure out how an audio company in that era could wind up with a name of Pulse Tec...
by mediatechnology
Sat Sep 25, 2010 8:19 am
Forum: Pro Audio Design
Topic: LC filter experiments, in Pultec MEQ context
Replies: 15
Views: 31722

Re: LC filter experiments, in Pultec MEQ context

You've got me curious about any non-audio work Pulse Techniques did. Wonder if they did military contracting...
by mediatechnology
Fri Sep 24, 2010 9:18 pm
Forum: Pro Audio Design
Topic: Centralized B+ and AC filament power distribution
Replies: 11
Views: 20689

Re: Centralized B+ and AC filament power distribution

Sure you don't have a spare 300-500W PC supply laying around? Seems like the 5V output could be modified to go to 6.3V. 15-20A is no load at all for those.
by mediatechnology
Fri Sep 24, 2010 8:53 pm
Forum: Pro Audio Design
Topic: LC filter experiments, in Pultec MEQ context
Replies: 15
Views: 31722

Re: LC filter experiments, in Pultec MEQ context

Doug: FWIW I look at this and see an AES paper in progress. Great work.
by mediatechnology
Fri Sep 24, 2010 8:35 pm
Forum: Pro Audio Design
Topic: Centralized B+ and AC filament power distribution
Replies: 11
Views: 20689

Re: Centralized B+ and AC filament power distribution

I have a stupid question: Why not use a switcher for the filaments? Is DC on the filaments the issue? If so, there seems to be a way to work around it. I haven't looked at a tube manual (other than the spine of one on the bookshelf) in years. Is capacitance from filament to grid a problem with HF ri...